Search

Peonía (1890), de Manuel Vicente Romerogarcía (1864-1917), ha sido leída por la crítica venezolana como la novela que inauguró el criollismo en ese país. Más allá de ese valor de primicia, la obra se ha juzgado con criterios muy disímiles, que van desde el rechazo acérrimo por considerarla como una obra de pocos méritos, a ser una pieza fundamental de las letras nacionales. Aquí se intenta mostrar ese supuesto estilo desprolijo y de discursos heterogéneos, que abarcan el melodrama, la sociología y el periodismo, entre otros, como una estrategia consciente que emplea el autor en su necesidad de representar la “realidad” venezolana.

Violencia, negociación y resolución de conflicto son conceptos usados en investigaciones sobre estos temas en las últimas décadas. Se refieren a ellos como parte de un proceso en constante transformación, de tal dimensión que podemos hablar de la violencia como mecanismo de resolución del conflicto (Meneses Reyes, 2020). Por ello en su análisis historiográfico es necesario entender los contextos como categoría de análisis (Montoya y Muñoz, 2018). Esta ponencia pretende analizar cómo la violencia representada en el autosacrificio revela un contexto que produjo la resolución del conflicto. El objeto de estudio es la fuerza especial kamikazes, durante la Segunda Guerra Mundial, que se debió a una combinación de distintos factores, incluyendo la creciente desesperación de Japón ante las derrotas militares y la presión de mantener su posición. La falta de recursos y la creencia en el honor y el deber, contribuyó a la aceptación de tácticas suicidas como una forma de resistencia extrema para la salvación de su gran imperio.

Abstract Parkinson’s disease (PD) is the second most common late-onset neurodegenerative disease and the predominant cause of movement problems. PD is characterized by motor control impairment by extensive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). This selective dopaminergic neuronal loss is in part triggered by intracellular protein inclusions called Lewy bodies, which are composed mainly of misfolded alpha-synuclein (α-syn) protein. We previously reported insulin-like growth factor 2 (IGF2) as a key protein downregulated in PD patients. Here we demonstrated that IGF2 treatment or IGF2 overexpression reduced the α-syn aggregates and their toxicity by IGF2 receptor (IGF2R) activation in cellular PD models. Also, we observed IGF2 and its interaction with IGF2R enhance the α-syn secretion. To determine the possible IGF2 neuroprotective effect in vivo we used a gene therapy approach in an idiopathic PD model based on α-syn preformed fibrils intracerebral injection. IGF2 gene therapy revealed a significantly preventing of motor impairment in idiopathic PD model. Moreover, IGF2 expression prevents dopaminergic neuronal loss in the SN together with a decrease in α-syn accumulation (phospho-α-syn levels) in the striatum and SN brain region. Furthermore, the IGF2 neuroprotective effect was associated with the prevention of synaptic spines loss in dopaminergic neurons in vivo. The possible mechanism of IGF2 in cell survival effect could be associated with the decrease of the intracellular accumulation of α-syn and the improvement of dopaminergic synaptic function. Our results identify to IGF2 as a relevant factor for the prevention of α-syn toxicity in both in vitro and preclinical PD models.

Abstract MicroRNAs are an emerging class of synaptic regulators. These small noncoding RNAs post-transcriptionally regulate gene expression, thereby altering neuronal pathways and shaping cell-to-cell communication. Their ability to rapidly alter gene expression and target multiple pathways makes them interesting candidates in the study of synaptic plasticity. Here, we demonstrate that the proconvulsive microRNA miR-324-5p regulates excitatory synapse structure and function in the hippocampus of mice. Both Mir324 knockout (KO) and miR-324-5p antagomir treatment significantly reduce dendritic spine density in the hippocampal CA1 subregion, and Mir324 KO, but not miR-324-5p antagomir treatment, shift dendritic spine morphology, reducing the proportion of thin, “unstable” spines. Western blot and quantitative Real-Time PCR revealed changes in protein and mRNA levels for potassium channels, cytoskeletal components, and synaptic markers, including MAP2 and Kv4.2, which are important for long-term potentiation (LTP). In line with these findings, slice electrophysiology revealed that LTP is severely impaired in Mir324 KO mice, while neurotransmitter release probability remains unchanged. Overall, this study demonstrates that miR-324-5p regulates dendritic spine density, morphology, and plasticity in the hippocampus, potentially via multiple cytoskeletal and synaptic modulators.

Abstract Alzheimer's disease (AD) is the most common neurodegenerative disorder, characterized by protein accumulation in the brain as a main neuropathological hallmark. Among them, Aβ42 peptides tend to aggregate and create oligomers and plaques. Macroautophagy, a form of autophagy characterized by a double-membrane vesicle, plays a crucial role in maintaining neuronal homeostasis by degrading protein aggregates and dysfunctional organelles as a quality control process. Recently, DEF8, a relatively uncharacterized protein, has been proposed as a participant in vesicular traffic and autophagy pathways. We have reported increased DEF8 levels in lymphocytes from mild cognitive impairment (MCI) and early-stage AD patients and a neuronal profile in a murine transgenic AD model. Here, we analyzed DEF8 localization and levels in the postmortem frontal cortex of AD patients, finding increased levels compared to healthy controls. To evaluate the potential function of DEF8 in the nervous system, we performed an in silico assessment of its expression and network profiles, followed by an in vivo evaluation of a neuronal Def8 deficient model using a Drosophila melanogaster model of AD based on Aβ42 expression. Our findings show that DEF8 is an essential protein for maintaining cellular homeostasis in the nervous system, and it is upregulated under stress conditions generated by Aβ42 aggregation. This study suggests DEF8 as a novel actor in the physiopathology of AD, and its exploration may lead to new treatment avenues.

Abstract The soil bacterium Pseudomonas putida KT2440 has been shown to produce selenium nanoparticles aerobically from selenite; however, the molecular actors involved in this process are unknown. Here, through a combination of genetic and analytical techniques, we report the first insights into selenite metabolism in this bacterium. Our results suggest that the reduction of selenite occurs through an interconnected metabolic network involving central metabolic reactions, sulphur metabolism, and the response to oxidative stress. Genes such as sucA, D2HGDH and PP_3148 revealed that the 2‐ketoglutarate and glutamate metabolism is important to convert selenite into selenium. On the other hand, mutations affecting the activity of the sulphite reductase decreased the bacteria's ability to transform selenite. Other genes related to sulphur metabolism (ssuEF, sfnCE, sqrR, sqr and pdo2) and stress response (gqr, lsfA, ahpCF and sadI) were also identified as involved in selenite transformation. Interestingly, suppression of genes sqrR, sqr and pdo2 resulted in the production of selenium nanoparticles at a higher rate than the wild‐type strain, which is of biotechnological interest. The data provided in this study brings us closer to understanding the metabolism of selenium in bacteria and offers new targets for the development of biotechnological tools for the production of selenium nanoparticles.

We studied the physicochemical characteristics and mycobiota associated to five key historic documents from Costa Rica, including the Independence Act of Costa Rica from 1821. We used nondestructive techniques (i.e., ATR-FTIR and XRF) to determine paper and ink composition. Results show that some documents are composed of cotton-based paper, whereas others were made of wood cellulose with an increased lignin content. We also determined that the ink employed in some of the documents is ferrogallic. Cultivation and molecular techniques were used to characterize the fungi inhabiting the documents. In total, 22 fungal isolates were obtained: 15 from the wood-cellulose-based documents and seven from the other three cotton-based. We also tested the cellulolytic activity of the recovered fungi; 95% of the fungi presented cellulolytic activity correlated to their ability to cause deterioration of the paper. Results suggest that cotton-based paper is the most resistant to fungal colonization and that most of the isolates have cellulolytic activity. This work increases the knowledge of the fungal diversity that inhabits historic documents and its relationship with paper composition and provides valuable information to develop strategies to conserve and restore these invaluable documents.

Technology in the modern world, has become a necessity electronic and mechanical parts are unified to become mechanisms, which are the facilitating devices of human life and work. A common problem in the fabrication of a product is the high costs of personnel and the physical limitations, an example is the production of the tower of Hanoi. Thus, taking into account the knowledge acquired of the different courses at the level of robotics, mechanics, electronics and programming, the design and construction of a manufacturing cell and its operating interface was carried out, which has as its main function the distribution and manipulation of the elements necessary for the assembly of a tower of Hanoi, to know the process that a company requires for the elaboration of a product in an automated way. For the development of this project, four different processes were considered, a supply stage through pneumatic circuits, machine vision algorithms for quality control of the parts involved in the assembly, a selection process and place developed by a Phantom type robot with 4 degrees of freedom and, finally, the delivery of the finished product by means of a conveyor belt for later packaging.

Plastics have become an ever-increasing environmental pollution problem since high amounts of them are dumped every year into the environment. To remediate this problem, many proposals attempt to produce new plastics with the same sound characteristics as the old ones, but with an increased biodegradability to remain only a few months in the environment before they can be turned into safe non-polluting natural products by microbes. One example of these materials is the polylactic acid-based plastic (PLA), which is presented as a biodegradable-compostable material but usually with a warning that they perform in this way under particular conditions. In this work, we evaluate the biodegradability of PLA and other plastics in a composting system under normal atmospheric conditions with an average temperature around 24 ºC in order to establish its compostability in typical conditions of tropical countries. Results obtained by monitoring the integrity and weight of plastic pieces and NMR over time reveal that none of the materials was biodegraded after 31 weeks (∼7 months) under the studied conditions. On the other hand, amplicon sequencing of the 16S rRNA showed the presence of bacterial groups identified previously on the degradation of biodegradable plastics (e.g., Methylotrophs and Actinobacteria) and are aligned with previous studies that conclude that plastics considered as biodegradable influence the soil microbiota. This work contributes to establishing which plastic materials should be classified as biodegradable in prevailing conditions in tropical countries.

Introducción: La ecocardiografía bidimensional es la técnica más efectiva para el diagnóstico del derrame pericárdico, gracias a sus altas sensibilidad y especificidad. Objetivo: Analizar la superioridad del método de suma de discos comparado con el método bidimensional en la estimación del derrame pericárdico por medio de ecocardiografía, tomando como referencia el volumen de líquido pericárdico extraído por pericardiocentesis o cirugía abierta. Método: Estudio retrospectivo de seguimiento de una cohorte basado en registros médicos y archivos de ecocardiografía. Se empleó un diseño pareado en el que cada imagen fue leída por el método bidimensional y por el método de suma de discos. Se incluyeron derrames pericárdicos graves, definidos clínicamente o por parámetros ecocardiográficos, que requirieran drenaje. El desempeño de los métodos de estimación bidimensional y de suma de discos, tomando como referencia la extracción por intervención, se cuantificó mediante áreas bajo la curva operador-receptor (auROC). Resultados: Se analizaron 40 registros, tomando como referencia el volumen obtenido por extracción; con un auROC de 0.81 (intervalo de confianza del 95% [IC95%]: 0.73-0.89), el desempeño diagnóstico del método de suma de discos fue significativamente mayor (p = 0.0335) que el del método bidimensional (auROC: 0.73; IC95%: 0.63-0.83). La estimación realizada por el método de suma de discos subestimó en promedio 51.3 ml (IC95%: −156.2-53.5). Conclusiones: En pacientes con derrame pericárdico e indicación de drenaje o taponamiento cardíaco, el método de suma de discos es superior en comparación con el método bidimensional en el estudio ecocardiográfico para la estimación cuantitativa del derrame pericárdico, ya que discrimina mejor respecto al método bidimensional.

Stata is one of the most widely used software for data analysis, statistics, and model fitting by economists, public policy researchers, epidemiologists, among others. Stata's recent release of version 16 in June 2019 includes an up-to-date methodological library and a user-friendly version of various cutting edge techniques. In the newest release, Stata has implemented several changes and additions that include: • Lasso • Multiple data sets in memory • Meta-analysis • Choice models • Python integration • Bayes-multiple chains • Panel-data ERMs • Sample-size analysis for CIs • Panel-data mixed logit • Nonlinear DSGE models • Numerical integration This review covers the most salient innovations in Stata 16. It is the first release that brings along an implementation of machine-learning tools. The three innovations we considered are: (1) Multiple data sets in Memory, (2) Lasso for causal inference, and (3) Python integration.

RIPK1 kinase activity is known to transduce a death signal, but the molecular mechanisms that normally prevent RIPK1 activation are unclear. Here, the authors report that IKK-mediated phosphorylation on RIPK1 Ser25 directly represses its enzymatic activity and thus RIPK1-dependent cell death.

Alzheimer’s disease (AD) is the most prevalent age-associated neurodegenerative disease. A decrease in autophagy during aging contributes to brain disorders by accumulating potentially toxic substrates in neurons. Rubicon is a well-established inhibitor of autophagy in all cells. However, Rubicon participates in different pathways depending on cell type, and little information is currently available on neuronal Rubicon’s role in the AD context. Here, we investigated the cell-specific expression of Rubicon in postmortem brain samples from AD patients and 5xFAD mice and its impact on amyloid β burden in vivo and neuroblastoma cells. Further, we assessed Rubicon levels in human-induced pluripotent stem cells (hiPSCs), derived from early-to-moderate AD and in postmortem samples from severe AD patients. We found increased Rubicon levels in AD-hiPSCs and postmortem samples and a notable Rubicon localization in neurons. In AD transgenic mice lacking Rubicon, we observed intensified amyloid β burden in the hippocampus and decreased Pacer and p62 levels. In APP-expressing neuroblastoma cells, increased APP/amyloid β secretion in the medium was found when Rubicon was absent, which was not observed in cells depleted of Atg5, essential for autophagy, or Rab27a, required for exosome secretion. Our results propose an uncharacterized role of Rubicon on APP/amyloid β homeostasis, in which neuronal Rubicon is a repressor of APP/amyloid β secretion, defining a new way to target AD and other similar diseases therapeutically.

In this paper, we present an implementation of selective harmonic elimination modulation technique in a 27-Level asymmetric multilevel converter. The main issue in this kind of converters is the generation of the gating patterns to obtain an optimized AC voltage waveform. State-of-the art solutions use deep mathematical analysis in the frequency domain by means of the Fourier series, but they are mainly applied for two-level or symmetric multilevel converters. On the other hand, the modulation for asymmetric multilevel converters is mainly focused on nearest level control or nearest vector control. In this work, we propose a novel modulating technique that takes advantage of the switching angles optimization for a 27-level waveform. In fact, different set of solutions are obtained and presented in order to define the modulation index as well as the value of the switching angles for the multilevel waveform. A modulation index sweep was performed for the entire operating region of the converter, where it can be observed that the number of levels decreases when the modulation index is low, which are calculated in order to minimize the total harmonic distortion (THD) of the resulting voltage waveform. In order to validate the proposal, these results for different modulation indexes values are simulated, obtaining a THD < 5% for a modulation index 0.75

La llamada Nueva crítica literaria latinoamericana fue un movimiento continental de renovación de los estudios literarios que surgió en la segunda mitad del siglo XX y que agrupó a destacados estudiosos como Ángel Rama, Antonio Cornejo Polar y Antonio Candido, entre otros. Vista en conjunto, su labor evidencia una persistente lucha por la construcción de un objeto de estudio (la literatura), de un sujeto de investigación (el crítico) y de un espacio inteligible (América Latina) propios, que dieran valor de originalidad y autonomía a una posible ciencia literaria de lo latinoamericano. La originalidad y objetivo de este artículo radica en la descripción y comprensión de la labor impulsada por la Nueva crítica literaria latinoamericana y su inserción en una larga tradición del discurso crítico que, en América Latina, inicia en el siglo XVII. Pensamos, al igual que de la Campa (1999), que es innegable el aporte de este conjunto de críticos al desarrollo de los estudios literarios latinoamericanos, cuya contribución derivó en un cambio de paradigma en la ciencia literaria que venía haciéndose en el continente, cuyo énfasis radicó en la idea de reenmarcar la obra literaria en su contexto antropológico y social, para que en esta nueva visión el crítico sirviera de sujeto político que coadyuvara a la transformación y reconstrucción de un nuevo espacio plural y democrático llamado “Latinoamérica”.

The use of renewable energies sources is taking great importance due to the high demand for electricity and the decrease in the use of fossil fuels worldwide. In this context, electricity generation through photovoltaic panels is gaining a lot of interest due to the reduction in installation costs and the rapid advance of the development of new technologies. To minimize or reduce the negative impact of partial shading or mismatches of photovoltaic panels, many researchers have proposed four configurations that depend on the power ranges and the application. The microinverter is a promising solution in photovoltaic systems, due to its high efficiency of Maximum Power Point Tracking and high flexibility. However, there are several challenges to improve microinverter’s reliability and conversion efficiency that depend on the proper control design and the power converter design. This paper presents a review of different control strategies in microinverters for different applications. The control strategies are described and compared based on stability, dynamic response, topologies, and control objectives. One of the most important results showed that there is little research regarding the stability and robustness analysis of the reviewed control strategies.

Agricultural mulches from plant waste constitute an ecological alternative due to their capacity to biodegrade and incorporate into the soil. This work aimed at evaluating, during a drought, the effects of a mat mulch, based on banana rachis and rice straw, on bell pepper (Capsicum annuum) production, and to characterize the material, both mechanically (traction resistance) and physical-chemically (water retention capacity, organic and inorganic components). Two contrasting irrigation regimes were used to determine the effect of the mat mulch on edaphic and productive parameters such as plant height, basal stem diameter, number of fruits and flowers, harvest, plant biomass, macro- and micronutrients in leaves, weeds/m2, and soil temperature. Treatments with the mat mulch resulted in increased height, number of fruits and flowers, biomass, and P, Zn and Cu concentrations. The mat mulch contributes to soil water retention, improves pepper agronomic variables response in plant’s height, basal stem diameter, and the number of flowers and fruits, especially with a low water irrigation regime. Furthermore, a 95% reduction in weed/m2, and soil temperature (18 °C) compared to air temperature (26.8 °C) was found. The characteristics of the waste-based mat mulch in soils offer new possibilities for environmentally friendly, efficient, and sustainable agricultural practices.

The universal tRNA modification t6A is found at position 37 of nearly all tRNAs decoding ANN codons. The absence of t6A37 leads to severe growth defects in baker’s yeast, phenotypes similar to those caused by defects in mcm5s2U34 synthesis. Mutants in mcm5s2U34 can be suppressed by overexpression of tRNALysUUU, but we show t6A phenotypes could not be suppressed by expressing any individual ANN decoding tRNA, and t6A and mcm5s2U are not determinants for each other’s formation. Our results suggest that t6A deficiency, like mcm5s2U deficiency, leads to protein folding defects, and show that the absence of t6A led to stress sensitivities (heat, ethanol, salt) and sensitivity to TOR pathway inhibitors. Additionally, L-homoserine suppressed the slow growth phenotype seen in t6A-deficient strains, and proteins aggregates and Advanced Glycation End-products (AGEs) were increased in the mutants. The global consequences on translation caused by t6A absence were examined by ribosome profiling. Interestingly, the absence of t6A did not lead to global translation defects, but did increase translation initiation at upstream non-AUG codons and increased frame-shifting in specific genes. Analysis of codon occupancy rates suggests that one of the major roles of t6A is to homogenize the process of elongation by slowing the elongation rate at codons decoded by high abundance tRNAs and I34:C3 pairs while increasing the elongation rate of rare tRNAs and G34:U3 pairs. This work reveals that the consequences of t6A absence are complex and multilayered and has set the stage to elucidate the molecular basis of the observed phenotypes.

Transfer RNAs (tRNAs) are the most post-transcriptionally modified RNA species. Some of these modifications, especially the ones located in the anti-codon loop, are required for decoding capabilities of tRNAs. Such is the case for 5-methoxy-carbonyl-methyl-2-thio-uridine (mcm5s2U), synthetized by the Elongator complex. Mutants for its sub-units display pleiotropic phenotypes. In this paper, we analyze the role of elp3 (Elongator catalytic sub-unit) in zebrafish development. We found that it is required for trunk development; elp3 knock-down animals presented diminished levels of mcm5s2U and sonic hedgehog (Shh) signaling activity. Activation of this pathway was sufficient to revert the phenotype caused by elp3 knockdown, indicating a functional relationship between Elongator and Shh through a yet unknown molecular mechanism.

Antecedentes: Las microalgas son fuente de compuestos fisiológicamente activos que pueden ser usados como ingredientes funcionales. De las microalgas del género Arthrospira (Spirulina) perteneciente a las algas verde-azules y cuyas especies más importantes son Arthrospira maxima y platensis, se tienen reportes de su uso en alimentación humana. Estas microalgas presentan una adecuada composición bioquímica para ser empleada como complemento alimenticio en desarrollo de productos novedosos Objetivo: Valorar el efecto de la suplementación de semolina de trigo con concentraciones de 5, 10 y 20% de Arthrospira platensis sobre calidad y aceptabilidad de pastas tipo espagueti, y realizar una evaluación física y química de la pasta seleccionada. Métodos: Se prepararon las pastas con la microalga y una pasta control (100% sémola), se sometieron a cocción para evaluar parámetros de calidad (tiempo cocción, peso, sólidos, proteínas solubles, firmeza instrumental), posteriormente se evaluaron con una prueba de aceptabilidad con 50 consumidores). A la pasta con la mayor aceptación se le analizó su composición proximal, fibra dietética, minerales, bioaccesibilidad de minerales, cómputo aminoacídico, índice glicémico y compuestos con potencial antioxidante. Los resultados de composición proximal y fibra dietética fueron comparados con los de la pasta control. Resultados: Al comparar las pastas con Arthrospira con la utilizada como control, se observó un efecto estadísticamente significativo de la adición de la microalga sobre incrementos de tiempo de cocción, peso, pérdidas de sólidos y proteínas y reducción de firmeza. La prueba de aceptabilidad entre las pastas suplementadas no varió con la sustitución de la sémola por 5 y 10% de la biomasa de la microalga, por lo cual se seleccionó la pasta con mayor sustitución para evaluar los parámetros de composición señalados. La pasta seleccionada presentó mayor contenido de proteínas, fibra dietética y cenizas (relacionadas con el contenido de minerales), con respecto al control, con cómputo de aminoácidos de 0,42 (deficiente lisina), índice glicémico intermedio y la presencia de compuestos con actividad antioxidante (polifenoles, carotenos y clorofila). Conclusión: La elaboración de pasta nutricional con la incorporación de A. platensis hasta un 10%, como ingrediente funcional en una mezcla de semolina, genera un producto de adecuada calidad nutricional, presencia de sustancias con reconocida capacidad antioxidante y aceptada por los consumidores.

Four basidiomycete fungi, Agaricus blazei Murrill (Agaricomycetideae), Ganoderma lucidum (W.Curt.: Fr.) P. Karst., Grifola frondosa (Dicks.: Fr.) S.F. Gray (Higher Basidiomycetes), and Pleurotus pulmonarius (Fr.) Quél. (Agaricomycetideae) were evaluated using three conservation methods for 12 months, recording their viability in order to establish the best conservation method. Growth kinetics, biomass, and polysaccharide production were studied. The conservation methods implemented included: distilled water at 24 °C; sawdust and rice bran with 10% glycerol at -20 °C; sawdust and rice bran with 10% glycerol at -80 °C; and freeze-drying of biomass with trehalose or skimmed milk. After conducting the analysis of the results after 12 months of conservation, we determined that the distilled water treatment at 24 °C was the best conservation method with the highest percentage of recoverability, at 83.3% during the 12th month, followed by the cryoconservation treatment at 80 °C, where 75% were recovered with no negative effects on biomass and polysaccharide production. The -20 °C and freeze-drying treatments were not effective; with cryoconservation at -20 °C treatment, strain recovery only occurred during the first month and with freeze-drying it was not possible to recover any strains during the entire 12-month period evaluated.

Grifóla frondosa es un hongo Basidiomycete comestible y medicinal que produce polisacáridos tipo glucanos (β-1,6 y β-1,3) con actividad antitumoral e inmunomoduladora. Para el presente trabajo, el objetivo fue evaluar la incidencia de diferentes fuentes de carbono (FC) en la producción de biomasa y exopolisacári-dos (EPS), bajo condiciones de cultivo sumergido, utilizando un diseño estadístico factorial con dos factores: fuente de carbono (FC(1-7)) y medio (MB y MS). La máxima producción de biomasa micelial (21,10 ± 0,82) g/l y la máxima producción de EPS (6,53 ± 0,14) g/l se logró utilizando el medio MB suplementado con FC4. Además de lo anterior, se logró desarrollar un medio de cultivo que cumple con el objetivo de disminuir costos, de Col $18.455 a $656 por litro de medio, produciendo (14,14 ± 0,82) g/l de biomasa y (5,16 ± 0,14) g/l de EPS, utilizando el medio MS suplementando con FC4. Estos resultados abren nuevas alternativas y posibilidades en nuestro país para el desarrollo de productos a partir de esta especie con costos que estén al alcance de la población.Grifóla frondosa is a Basidiomycete fungus edible and medicinal, it produces polysaccharides such a glucans (β-1,6 and β-1,3) with anti-tumor and inmuno-stimulating activity. For this work, the aim was evaluate the incidence of different carbon sources (FC) in biomass and exo-polymer (EPS) production, under submerged culture conditions, by using a factorial statistical design with two factors: carbon source (FC(1-7)) and medium (MB and MS). The maximal yield of mycelial biomass (21,10 ± 0,82) g/l and the maximal yield in EPS (6,53 ± 0,14) g/l was achieved by using the MB medium supplemented with FC4. Besides, it was possible to develop a medium that fulfills the objective of reducing costs from $18.455 to $656 Colombian pesos for each liter of medium used, which produces (14,14 ± 0,82) g/l of biomass and (5,16 ± 0,14) g/l of EPS, using the MS medium supplemented with FC4. This result opens new alternatives and possibilities in our country for developing products of this species with cost that can be reached by population.

Los resultados que arrojan los modelos hidrológicos utilizados actualmente en la planeación de obras hidráulicas en México no han favorecido la disminución de los efectos generados por los fenómenos meteorológicos relativos a la lluvia y el escurrimiento en los núcleos poblacionales. La escasa información de medición de caudales; dato imprescindible en la determinación de la certeza de los resultados y parámetro primordial en la toma de decisiones en materia de diseño, construcción y operación de proyectos de infraestructura pluvial o sanitaria, motiva la utilización de instrumentos tecnológicos que asemejen con mayor precisión el comportamiento hídrico real, a través de la aplicación de modelos que integren la variabilidad espacial y temporal de la lluvia, cuyos resultados favorezcan las dinámicas económicas sociales y ambientales en los centros urbanos. Palabras clave: cuenca urbana, incertidumbre, modelos hidrológicos, software, vulnerabilidad.

Carotid artery injuries with pseudoaneurysm are uncommon but associated with central neurologic dysfunction. We present a case of posttraumatic pseudoaneurysm of the right common carotid artery treated by implantation of a covered stent. A 44-year-old woman with multiple injuries after fall from height presents a small dissection flap of the right common carotid artery (RCCA) on the initial computed tomography angiography (CTA). Fifteen days later a 10 mm pseudoaneurysm is observed on control CTA. We decided endovascular treatment. Through right femoral access with a long introducer sheath placed in the innominate artery, we implanted a covered stent Advanta V12 9×38 mm in the RCCA. The patient was discharged from the hospital with antiplatelet therapy without any neurological dysfunction and complete exclusion of the pseudoaneurysm. Use of covered stents has emerged as a safe and effective alternative to surgical repair of carotid injuries.

In this article, we reflect on the possibilities that literature and publicity offer to the foreign language teacher as a cultural mediator. We aim at a double objective: on the one hand, from a critical view, we will try to point out some of the interpretations of literary texts that are made in publicity, mainly through different processes of intertextualisation; on the other hand, from the perspective of the didactics of foreign languages, we will look into the literary and cultural references that appear in publicity on TV and will propose a didactic model which will be developed with two different commercials.

Transfer RNAs (tRNAs) harbor a subset of post‐transcriptional modifications required for structural stability or decoding function. N6‐threonylcarbamoyladenosine (t6A) is a universally conserved modification found at position 37 in tRNA that pair A‐starting codons (ANN) and is required for proper translation initiation and to prevent frame shift during elongation. In its absence, the synthesis of aberrant proteins is likely, evidenced by the formation of protein aggregates. In this work, our aim was to study the relationship between t6A‐modified tRNAs and protein synthesis homeostasis machinery using Drosophila melanogaster. We used the Gal4/UAS system to knockdown genes required for t6A synthesis in a tissue and time specific manner and in vivo reporters of unfolded protein response (UPR) activation. Our results suggest that t6A‐modified tRNAs, synthetized by the threonyl‐carbamoyl transferase complex (TCTC), are required for organismal growth and imaginal cell survival, and is most likely to support proper protein synthesis.

Antecedentes: Las microalgas son fuente de compuestos fisiológicamente activos que pueden ser usados como ingredientes funcionales. De las microalgas del género Arthrospira (Spirulina) perteneciente a las algas verde-azules y cuyas especies más importantes son Arthrospira maxima y platensis, se tienen reportes de su uso en alimentación humana. Estas microalgas presentan una adecuada composición bioquímica para ser empleada como complemento alimenticio en desarrollo de productos novedosos Objetivo: Valorar el efecto de la suplementación de semolina de trigo con concentraciones de 5, 10 y 20% de Arthrospira platensis sobre calidad y aceptabilidad de pastas tipo espagueti, y realizar una evaluación física y química de la pasta seleccionada. Métodos: Se prepararon las pastas con la microalga y una pasta control (100% sémola), se sometieron a cocción para evaluar parámetros de calidad (tiempo cocción, peso, sólidos, proteínas solubles, firmeza instrumental), posteriormente se evaluaron con una prueba de aceptabilidad con 50 consumidores). A la pasta con la mayor aceptación se le analizó su composición proximal, fibra dietética, minerales, bioaccesibilidad de minerales, cómputo aminoacídico, índice glicémico y compuestos con potencial antioxidante. Los resultados de composición proximal y fibra dietética fueron comparados con los de la pasta control. Resultados: Al comparar las pastas con Arthrospira con la utilizada como control, se observó un efecto estadísticamente significativo de la adición de la microalga sobre incrementos de tiempo de cocción, peso, pérdidas de sólidos y proteínas y reducción de firmeza. La prueba de aceptabilidad entre las pastas suplementadas no varió con la sustitución de la sémola por 5 y 10% de la biomasa de la microalga, por lo cual se seleccionó la pasta con mayor sustitución para evaluar los parámetros de composición señalados. La pasta seleccionada presentó mayor contenido de proteínas, fibra dietética y cenizas (relacionadas con el contenido de minerales), con respecto al control, con cómputo de aminoácidos de 0,42 (deficiente lisina), índice glicémico intermedio y la presencia de compuestos con actividad antioxidante (polifenoles, carotenos y clorofila). Conclusión: La elaboración de pasta nutricional con la incorporación de A. platensis hasta un 10%, como ingrediente funcional en una mezcla de semolina, genera un producto de adecuada calidad nutricional, presencia de sustancias con reconocida capacidad antioxidante y aceptada por los consumidores.

Este trabajo analiza la relevancia de la actividad turística y su posible impacto sobre la economía costarricense, desde un punto de vista teórico. La ausencia de estudios formales cercanos a la realidad costarricense, y la utilización de políticas e incentivos para la promoción del turismo hacen necesaria esta investigación. Primero, se analizan los diferentes modelos que se han desarrollado en la literatura. Luego se construye un modelo que se acerca a las condiciones de la economía de Costa Rica. La construcción de dicho modelo es el principal objetivo de esta investigación. De forma específica, se tiene por objetivo discutir las siguientes preguntas: 1) ¿Cuál es el posible resultado sobre la producción interna, de largo plazo, de un aumento del gasto de los turistas?, 2) ¿En el largo plazo, qué sectores pueden ver aumentada su producción y que sectores pueden verla disminuida ante un aumento del gasto de los turistas? y, 3) ¿Cuál es el comportamiento esperado de los precios relativos, de largo plazo, ante un aumento del gasto de los turistas?

Un artista chileno, quien estudia y practica varios géneros como dibujo, música, animación digital y producción cinematográfica. En este numero se presenta una segunda selección de sus pinturas realizadas según una innovadora técnica de arte digital.

Most intrinsic death signals converge into the activation of pro-apoptotic BCL-2 family members BAX and BAK at the mitochondria, resulting in the release of cytochrome c and apoptosome activation. Chronic endoplasmic reticulum (ER) stress leads to apoptosis through the upregulation of a subset of pro-apoptotic BH3-only proteins, activating BAX and BAK at the mitochondria. Here we provide evidence indicating that the full resistance of BAX and BAK double deficient (DKO) cells to ER stress is reverted by stimulation in combination with mild serum withdrawal. Cell death under these conditions was characterized by the appearance of classical apoptosis markers, caspase-9 activation, release of cytochrome c, and was inhibited by knocking down caspase-9, but insensitive to BCL-X(L) overexpression. Similarly, the resistance of BIM and PUMA double deficient cells to ER stress was reverted by mild serum withdrawal. Surprisingly, BAX/BAK-independent cell death did not require Cyclophilin D (CypD) expression, an important regulator of the mitochondrial permeability transition pore. Our results suggest the existence of an alternative intrinsic apoptosis pathway emerging from a cross talk between the ER and the mitochondria.

Se describen los objetivos y funcionamiento del programa eTwinning de hermanamientos escolares a través de Internet. Se hace balance del programa a nivel nacional aportándose datos de participación y desta-cando los factores que lo han convertido en una de la acciones de mayor aceptación entre el profesorado para establecer proyectos de aprendizaje colaborativo con otros países.